Summary:
- In the 1950s, astronomers at the Palomar Observatory in California noticed strange, transient flashes on photographic plates used to capture images of the night sky.
- These flashes were brief and unpredictable, lasting only a fraction of a second, and their origin remained a mystery for many years.
- Further analysis of the archived photographic plates has revealed that these flashes may have been caused by high-energy cosmic rays interacting with the photographic emulsion, providing insights into the nature of these energetic particles in the universe.